What do I need to do to win a arm wrestle against my boyfriend? I came close to winning but could not get him down?

I work out 5 days a week each 3 hours sessions. I work my entire body unlike my boyfriend who works out 90% upperbody. He only works out 3 times a week for a hour. We had 7 matches. First 3 he got me faster then the last two. On the last two I almost pinned him but in the end he came back to beat me. I am a strong woman with good muscle development yet still feminine looking. 168cm 65 kilos. Any tips?

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I can out do him in push ups 50 to 31 and I work out 5 days a week 3 hours a session
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Another women who knows how to arm wrestle but has less muscles then I did beat my boyfriend. My boyfriend is stronger but still lost to her. I know its possible I can beat him too.
What do I need to do to win a arm wrestle against my boyfriend? I came close to winning but could not get him down?
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